Morphotectonic assessment in the Tokaj Mountain region (Hungary)

The Tokaj Mountain is a part of the large Carpathian Volcanic Arc which was active in the Middle-Upper Miocene in this area. It is built up of mainly andesitic and dacitic volcanic-sedimentary sequence which filled up the 1.5-3 km deep tectonic basin between two strike-slip faults: the Hernád Fault (W) and the Bodrog Fault (SE). Though the most tectonically active phase was during the Miocene, minor recent tectonism is observed in the area in the form of rare 2 to 3 M earthquakes. Due to its relatively low activity, the complexity and the thickness of the volcano-sediments, the tectonism and its effect on the recent shape of the mountain was not accurately mapped.

The present study aims to reveal the possible connections between the morphology and the present day stress field of the area. In this regard, several stress field model has been generated with the web based application “Geonuleus” accompanied with morphotectonic statistical analyses of the DEM from the region.

The method is based on the categorization of neotectonic lineaments (faults) by their geodynamic properties using the TPO method (Type-Property-Orientation) naming system for eventually generate the active stress field that reigns the region (Albert et al. 2016). The ALOS Palsar DEM (12.5 m resolution) has been used for the morphotectonic study. During the process, multiple filter have been utilized to eliminate the noise and to highlight lineaments (e.g. directional perpendicular filters). A statistical analysis was done from the lineaments orientation in order to define the general trend and to compare it with the main neotectonic directions and the stress field that have produced them.

The study area concentrated on the western part of the mountain since the detailed geophysical data is available only from that area (Bodor, 2011). The area was subdivided into three region based on the difference of the lithology, the tectonic regime and the topography (northern area, the western side of the Hernád stream and the eastern side of the Hernád stream). The result of the modeling shows a confluence between the two methods (SFM and the morphometry) especially in the western part with a regional N-S stress orientation. In the eastern side the flexure is clearly highlighted by stress trend movement. It is important to report that the model could be enhanced with further detailed data.

From the part of G.A. financial support was provided from the NRDI Fund of Hungary, Thematic Excellence Programme no. TKP2020-NKA-06 (National Challenges Subprogramme) funding scheme.

References:

Albert, G., Barancsuk, Á., & Szentpéteri, K. 2016. Stress field modelling from digital geological map data. Geophysical Research Abstracts, v. 18, EGU2016-14565.

Bodor B. 2011: A Hernád-árok szerkezetföldtani vizsgálata. MSc thesis, Eötvös University, Dept. Regional Geology, 99 p